drivers/input/misc/da9052_onkey.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * ON pin driver for Dialog DA9052 PMICs
   4  *
   5  * Copyright(c) 2012 Dialog Semiconductor Ltd.
   6  *
   7  * Author: David Dajun Chen <dchen@diasemi.com>
   8  */
   9
  10 #include <linux/input.h>
  11 #include <linux/module.h>
  12 #include <linux/platform_device.h>
  13 #include <linux/workqueue.h>
  14
  15 #include <linux/mfd/da9052/da9052.h>
  16 #include <linux/mfd/da9052/reg.h>
  17
  18 struct da9052_onkey {
  19         struct da9052 *da9052;
  20         struct input_dev *input;
  21         struct delayed_work work;
  22 };
  23
  24 static void da9052_onkey_query(struct da9052_onkey *onkey)
  25 {
  26         int ret;
  27
  28         ret = da9052_reg_read(onkey->da9052, DA9052_STATUS_A_REG);
  29         if (ret < 0) {
  30                 dev_err(onkey->da9052->dev,
  31                         "Failed to read onkey event err=%d\n", ret);
  32         } else {
  33                 /*
  34                  * Since interrupt for deassertion of ONKEY pin is not
  35                  * generated, onkey event state determines the onkey
  36                  * button state.
  37                  */
  38                 bool pressed = !(ret & DA9052_STATUSA_NONKEY);
  39
  40                 input_report_key(onkey->input, KEY_POWER, pressed);
  41                 input_sync(onkey->input);
  42
  43                 /*
  44                  * Interrupt is generated only when the ONKEY pin
  45                  * is asserted.  Hence the deassertion of the pin
  46                  * is simulated through work queue.
  47                  */
  48                 if (pressed)
  49                         schedule_delayed_work(&onkey->work,
  50                                                 msecs_to_jiffies(50));
  51         }
  52 }
  53
  54 static void da9052_onkey_work(struct work_struct *work)
  55 {
  56         struct da9052_onkey *onkey = container_of(work, struct da9052_onkey,
  57                                                   work.work);
  58
  59         da9052_onkey_query(onkey);
  60 }
  61
  62 static irqreturn_t da9052_onkey_irq(int irq, void *data)
  63 {
  64         struct da9052_onkey *onkey = data;
  65
  66         da9052_onkey_query(onkey);
  67
  68         return IRQ_HANDLED;
  69 }
  70
  71 static int da9052_onkey_probe(struct platform_device *pdev)
  72 {
  73         struct da9052 *da9052 = dev_get_drvdata(pdev->dev.parent);
  74         struct da9052_onkey *onkey;
  75         struct input_dev *input_dev;
  76         int error;
  77
  78         if (!da9052) {
  79                 dev_err(&pdev->dev, "Failed to get the driver's data\n");
  80                 return -EINVAL;
  81         }
  82
  83         onkey = kzalloc(sizeof(*onkey), GFP_KERNEL);
  84         input_dev = input_allocate_device();
  85         if (!onkey || !input_dev) {
  86                 dev_err(&pdev->dev, "Failed to allocate memory\n");
  87                 error = -ENOMEM;
  88                 goto err_free_mem;
  89         }
  90
  91         onkey->input = input_dev;
  92         onkey->da9052 = da9052;
  93         INIT_DELAYED_WORK(&onkey->work, da9052_onkey_work);
  94
  95         input_dev->name = "da9052-onkey";
  96         input_dev->phys = "da9052-onkey/input0";
  97         input_dev->dev.parent = &pdev->dev;
  98
  99         input_dev->evbit[0] = BIT_MASK(EV_KEY);
 100         __set_bit(KEY_POWER, input_dev->keybit);
 101
 102         error = da9052_request_irq(onkey->da9052, DA9052_IRQ_NONKEY, "ONKEY",
 103                             da9052_onkey_irq, onkey);
 104         if (error < 0) {
 105                 dev_err(onkey->da9052->dev,
 106                         "Failed to register ONKEY IRQ: %d\n", error);
 107                 goto err_free_mem;
 108         }
 109
 110         error = input_register_device(onkey->input);
 111         if (error) {
 112                 dev_err(&pdev->dev, "Unable to register input device, %d\n",
 113                         error);
 114                 goto err_free_irq;
 115         }
 116
 117         platform_set_drvdata(pdev, onkey);
 118         return 0;
 119
 120 err_free_irq:
 121         da9052_free_irq(onkey->da9052, DA9052_IRQ_NONKEY, onkey);
 122         cancel_delayed_work_sync(&onkey->work);
 123 err_free_mem:
 124         input_free_device(input_dev);
 125         kfree(onkey);
 126
 127         return error;
 128 }
 129
 130 static int da9052_onkey_remove(struct platform_device *pdev)
 131 {
 132         struct da9052_onkey *onkey = platform_get_drvdata(pdev);
 133
 134         da9052_free_irq(onkey->da9052, DA9052_IRQ_NONKEY, onkey);
 135         cancel_delayed_work_sync(&onkey->work);
 136
 137         input_unregister_device(onkey->input);
 138         kfree(onkey);
 139
 140         return 0;
 141 }
 142
 143 static struct platform_driver da9052_onkey_driver = {
 144         .probe  = da9052_onkey_probe,
 145         .remove = da9052_onkey_remove,
 146         .driver = {
 147                 .name   = "da9052-onkey",
 148         },
 149 };
 150 module_platform_driver(da9052_onkey_driver);
 151
 152 MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");
 153 MODULE_DESCRIPTION("Onkey driver for DA9052");
 154 MODULE_LICENSE("GPL");
 155 MODULE_ALIAS("platform:da9052-onkey");